Expert Opinion: How Long Does Mobil 1 Synthetic Oil Last?

With Mobil 1 annual protection, you can keep your vehicle running for 20,000 miles or a full year. You can purchase it in 3 viscosity grades right now: 0w-20, 5W-20, and 5W-30.

As exciting as it is to think that you can save yourself a lot of time and effort in the long run through the use of motor oil that is good enough to last long 20,000 miles, it also makes you curious about it.

The purpose of this article is to answer three major questions. Defining synthetic oils, how they differ from conventional oils, and how long does Mobil 1 synthetic oil last?

What is Synthetic Oil made from?

A conventional motor oil consists of a base oil and an additive package, and that base oil determines whether it’s synthetic or conventional.

In order to make things as convenient as possible, base oils are grouped as follows: 1, 2, 3, 4, and 5.

The first three groups of oil are derived from crude oil, which is derived from organic material, as opposed to group 4, which is made up of polyalphaolefins, which are synthetic products, and then group 5, which is everything else not included in group 1, 2, 3, and 4.

Synthetic motor oils, on the other hand, are based on groups 3, 4, and 5 and are not allowed to be classified as conventional motor oils. 

There is some crossover between groups 2 and 3 because group 3 base oils have enough of a chemical difference in refinement that they can be classified as synthetic motor oils.

Related Guide: How Long Does Conventional Oil Last

Why is Synthetic Oil better than Conventional?

It is reported that a study was conducted recently in which five different brands of 5w-20 synthetic oil were used, along with conventional oil. The two oils were then tested according to ASTM standards and they discovered that synthetic oils were 47% better at performing 8 different tests compared with conventional oils. That was a pretty great improvement and was really cool.

Let’s take a look at four of the major differences between synthetics and conventional oils.

Shear Stability

The viscosity improvers in conventional oils expand out at higher temperatures, so you can keep a nice thick boundary layer between moving metal parts at higher temperatures when you use conventional oils.

In this case, there is no damage, but these viscosity improvers start shearing and sort of breaking off into smaller molecules, which thins out the oil. Because conventional oils do not have the inherent properties that synthetic oils do, they will use more of this.

As a result, these viscosity improvers will break down over time, and the oil will thin out at higher temperatures, making it incapable of providing you with the perfect protection. Due to the thinned-out material, there will be more metal-to-metal contact, resulting in more wear.

Best Mobil 1 Motor Oils

Best Overall
Mobil 1 Advanced Fuel Economy Full Synthetic Motor Oil 0W-20

  • Car, Truck
  • Outstanding Engine Performance
  • 10,000 miles, Heat protection from 500 degrees F to -40 degrees F
Best Overall
Mobil 1 Extended Performance Full Synthetic Motor Oil 0W-20

  • Car
  • 20,000 miles
  • Outstanding Engine Performance,
Best Overall
Mobil 1 High Mileage Full Synthetic Motor Oil 0W-20

  • Car
  • 10,000 miles
  • For Engines with over 75,000 miles

Every product was carefully curated by an Esquire editor. We may earn a commission from these links.

Temperature-dependent Pumpability

When you start your car in a very cold climate, say – 20 degrees Celsius outside, you’ll need that engine oil to flow immediately. This is important in super cold climates when you start your car.

Basically, now conventional oils here even have the same viscosity rating as 5w-20, so you are not starving the engine of oil.

Even at lower temperatures, it will still perform poorly. At much lower temperatures, synthetic oils maintain the properties that allow them to flow at the same viscosity rating as conventional oils. Synthetic motor oils are recommended for cold starts.


In essence, it refers to how easily this oil evaporates.

Conventional oils do not have well-organized and well-grouped molecules like synthetic oils do. Due to the varied size of the molecules, there is a bit more randomness due to which these low-weight molecules can evaporate and burn off in the engine causing a thick oil.

Because thicker oil will not flow the same as the original oil, fewer flow results in less oil going to where it needs to go.

Oxidation Stability

Conventional oils are going to change greatly with time if they are exposed to high pressures and air, and oxidation breaks them down.

In oil, you will notice that viscosity gets pushed out at higher temperatures as a result of the volatile nature of conventional oils, which causes more of those smaller molecules to burn off, but also as a result of oxidation.

Synthetic oils maintain their original properties longer, which means that they are more effective in protecting you. They are thin ones at cooler temperatures and thick ones to maintain film thickness at higher temperatures while maintaining flow at those cold temperatures. 

Related Article: What are the Characteristics and Requirements for Good Lubricants? [Explained] (2022)

How Long Does Mobil 1 Synthetic Oil Last?

Does Mobil 1 Really Last 20000 miles?

The Mobil 1 annual protection formula was developed with the goal of pushing the boundary on synthetic oils even further, and finding a way to increase their breakdown resistance even further it must retain its original viscosity for an extended period of time so that the oil could last for a year or twenty thousand miles (32186.88 Km) between oil changes.

Despite keeping viscosity, you still need to account for deposits and sludge, which means if you start forming deposits where metal is in contact with metal, you won’t be able to maintain that flow.

Even if the oil is thin enough to flow through, deposits and sludge can impede it, and the images that came up actually demonstrate this, and sludge was not an issue with these 20,000-mile intervals because they didn’t really have deposit formation. The wear prevention was seen as neat too. 

To check Mobil 1 annual protection will last long approximately 20,000 miles, the engines were torn down, but they maintained proper flow and they knew that one would look at these parts and measure their manufacturing tolerances for those 20,000 miles.

The parts were actually within specs for brand-new ones. So basically nothing had happened. The Lexus NX 200t crankshaft bearings have been photographed after 20,000 miles and can be found on their website.


1. When should I change my Mobil 1 synthetic oil?

Providing excellent protection, Mobil Super oils have a service life of 5,000 – 7,500 miles. With Mobil 1, you can expect superior protection and performance for up to 15,000 miles between oil changes.

2. Can Mobil 1 go 20000 miles?

Extended Performance 0W-20 advanced full synthetic motor oil delivers outstanding engine protection and helps protect crucial engine parts for up to 20,000 miles.

3. Why is Mobil 1 oil the best?

Unlike conventional engines, Mobil 1 reaches maximum efficiency much sooner because it works faster. With Mobil 1, you get less friction and better fuel economy as a result of its strong antioxidant system that prevents oxidation and thickening of the oil.

4. What is the difference between Mobil full synthetic and Mobil 1?

As a result of their laboratory modification, Mobil 1 motor oils are referred to as Full Synthetics. Mineral oils that have been hydrocracked are usually what they are. It is sometimes possible for them to be nearly 100% synthetic, but if some mineral oil is included as a carrier oil, this causes them to be only fully synthetic.

5. Who makes Mobil 1 engine oil?

Synthetic motor oil and other automotive lubrication products are sold under the Mobil 1 brand. Mobil oil developed it, but ExxonMobil now markets and sells it globally. Oil for engines was introduced in 1974 by Mobil 1.


At a microscopic level, it isn’t a smooth interaction between metals on metals. It is quite rough, so you need to keep the film thin and flow properly to prevent wear. Those are what they’re able to do now. Just because you can go a year or 20,000 miles without changing your oil does not mean you can ignore your other maintenance obligations.

If your car is still under warranty, follow the warranty requirements and keep track of your regular maintenance intervals.

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